The present invention relates to low molecular weight silicone polyether ABA type block copolymers that are useful to imparting a hydrophilic coating to the surface of either woven or non-woven textiles.
Textiles are made from a variety of materials both natural and man made. Natural textiles include cotton, wool, silk, linen and the like while synthetic textiles are derived from various high polymers such as polyesters, polyamides, polyimides, and the various polyolefins, e.g. polyethylene, polypropylene, polybutylene. While polymers are used extensively to make a variety of products ranging from blown and cast films, extruded sheets, injection molded articles, foams, blow molded articles, extruded pipe, monofilaments and non-woven webs many of the polymers used for such materials are hydrophobic. In many cases this property is an advantage.
There are a number of uses to which polymers may be put where their hydrophobic nature either limits their usefulness or requires some modification. This is particularly true of polyolefins such as polyethylene and polypropylene which are used to manufacture polymeric fabrics which are used in disposable absorbent articles such as diapers, training pants, incontinence products, wipes, feminine care products and the like. These polymeric fabrics are typically non-woven webs prepared by meltblowing, coforming or spunbonding. For uses such as the foregoing these non-woven fabrics need to be wettable. Frequently wettability can be obtained by coating the fabric in some fashion with a treatment solution during or after formation of the fabric web and drying the web.
Some of the more commonly applied topically applied treatments are nonionic treatments, for example polyethoxylated octylphenols and the condensation products of propylene oxide with propylene glycol. These types of treatments are effective in rendering normally hydrophobic polymeric fabrics wettable or hydrophilic. However, the treatment is readily removed from the fabric, often after only a single exposure to an aqueous liquid.
There have been several different approaches to increasing the durability of treatments that are topically applied to the surface of a fabric. Among these approaches have been:
(1) the use of a composition that includes water, a primary treatment, and a co-treatment that functions to wet the fabric with the treatment composition and that provides for a substantially uniform distribution of the primary treatment onto the fabric;
(2) the use of a treatment, with or without a nonionic co-treatment that is the reaction product of an acid anhydride derivative with a polyhydroxy compound, polyethylene glycol, triethanolamine, a polyhydroxyamine, and certain unsaturated aliphatic sulfo compounds;
(3) the use of a treatment, with or without a nonionic co-treatment that is the reaction product of certain unsaturated aliphatic sulfo compounds with the reaction product of an acid anhydride derivative with a polyamine having at least one NH group capable of addition to a double bond;
(4) the use of a treatment mixture that includes an ester acid, ester salt, or a mixture thereof, and an amide-acid, amide-salt or mixture thereof with or without a nonionic co-treatment;
(5) the use of a treatment mixture that includes a sorbitol succinate treatment and a co-wetting aid that can be a silicone polyether or a primary or secondary alcohol; and
(6) the use of a silicone polyether treatment having the formula: 
xe2x80x83where R1 and R6 are selected from the group of hydrogen and C1-8 alkyl and aryl, R2, R3, R4 and R5 are selected from the group of C1-8 alkyl and aryl, the subscript a represents an integer ranging from about 8 to about 25, the subscript b represents an integer ranging from about 8 to about 25, the ratio of b to a is in a range of from about 0.7 to about 1.5, the subscript c represents an integer from 1 to about 10, the subscript d represents an integer of from about 40 to about 70 the ratio of d to two times the sum of a and b is in a range of from about 0.7 to about 1.5 and the number average molecular weight is preferably in a range of from about 5,000 to about 35,000, more preferably from about 6,500 to about 18,500 and most preferably about 7,000.
The examples of U.S. Pat. No. 5,540,984 (""984) teach that silicone polyether treatments having a molecular weight below about 7,000 do not provide the durability provided by patentee""s invention. Further, the polyether endgroups on the silicone treatments employed by the ""984 patent ranged from about 50 to 80 weight percent propylene oxide and from about 50 to about 20 weight percent ethylene oxide. The ""984 patent specifically teaches that reversing this weight ratio of polyether end groups to 85 weight percent ethylene oxide and 15 weight percent propylene oxide (patentee""s example P) does not provide a durable hydrophilic coating as defined by patentee. This is emphasized by patentee""s results for a silicone polyether treatment having 100 weight per cent ethylene oxide polyether groups wherein the treatment was not durable (patentee""s example J). Thus, the ""984 patent teaches that the polyether substituents of the silicone polyether treatment must contain a mix of ethylene oxide and propylene oxide groups or preferably all propylene oxide groups. These results were obtained for copolymers terminated with the respective polyether moieties.
Notwithstanding the advances that have been made in rendering fabrics wettable by providing for a hydrophilic coating there remains a need for further improvement in these areas.
The present invention provides for a treatment silicone compound selected from the group consisting of:
1) polysiloxane polyethers having the formula:
((R1O(C2H4O)a(CH2)b)3-cR2SiO1/2)2(R3R3SiO)d
where R1 is selected from the group consisting of hydrogen and alkyls and R2 and R3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about 1 to about 8; the subscript b ranges from about 1 to about 10; the subscript c ranges from zero to 2; the subscript d ranges from about to 1 to about 10; and the number average molecular weight ranging from ranges from about to 300 to about 1,000.
2) polysiloxane polyethers having the formula:
((R1O(CHCH3CH2O)a(CH2)b)3-cR2SiO1/2)2(R3R3SiO)d,
where R1 is selected from the group consisting of hydrogen and alkyls and R2 and R3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about to 1 to about 8; the subscript b ranges from about 1 to about 10; the subscript c ranges from zero to 2; the subscript d ranges from about to 1 to about 10; and the number average molecular weight ranging from ranges from about to 300 to about 1,000;
3) polysiloxane polyethers having the formula: 
xe2x80x83where R1 is selected from the group consisting of hydrogen and alkyls and R2 and R3 are each independently selected from the group consisting of one to forty carbon atom monovalent hydrocarbon radicals; the subscript a ranges from about to 1 to about 8; the subscript b ranges from about 1 to about 10; the subscript c ranges from zero to 2; the subscript d ranges from about to 1 to about 10; the subscript e ranges from about to 1 to about 10; and the number average molecular weight ranging from ranges from about to 300 to about 1,000; and
5) mixtures thereof.
Such treatment silicone compositions are useful for treating fabrics comprised of natural or synthetic polymeric materials to render the fabrics hydrophilic, i.e. capable of picking up and absorbing quantities of water. Such treatment silicone compositions are useful for treating cellulosic materials such as paper.